In conventional power supply apparatuses such as power storage apparatuses including secondary batteries and electric double layer capacitors and fuel cells, a power supply unit including a plurality of power supply elements (battery cells) stacked with each other is housed in a case formed of an upper case and a lower case. The power supply unit (assembled battery, battery module) is secured to the lower case by a fastening member such as a bolt.
The power supply apparatus including the power supply unit housed in the case is fixed to a vehicle body (floor) with the lower case (and/or the upper case) for mounting on the vehicle.
FIG. 8 is a section view showing the conventional power supply apparatus which is formed of a case member including an upper case 10 and a lower case 20 and a power supply unit (power supply module) 30 including a plurality of power supply elements (battery cells, power storage cells, fuel cells or the like) 35 stacked with each other and housed in the case member. The power supply unit 30 is fastened and fixed to the lower case 20, and an extending portion formed in each of the upper case 10 and the lower case 20 is fastened and fixed to a vehicle body 1, thereby mounting the power supply apparatus on the vehicle. Each of the plurality of the power supply elements 35 constituting the power supply unit 30 is formed of a power generation (power storage) element (diagonally shaded area in FIG. 8) and a resin member covering the power generation element. A fastening portion 34 formed in the power supply unit 30 is secured to the lower case 20 by a fastening member 40 in a vertical direction of the power supply unit 30.
Patent Document 1 has described a battery pack in which, in view of the effect of stress from thermal expansion of a power supply unit on a case, the power supply unit is fastened to a lower case by interposing an end plate. In the battery pack described in Patent Document 1, the lower case is not directly fastened to the end plate but is secured thereto with a rail member interposed therebetween.    [Patent Document 1] Japanese Patent Laid-Open No. 2005-141036 (FIGS. 1, 2, and the like)    [Patent Document 2] Japanese Patent Laid-Open 2004-071281